1. Field of the Invention
The present invention mainly relates to a power supply device that can be used as large current power supplies for electric motor for driving cars such as hybrid car and electric vehicle, and as electric power storages for home use and manufacturing plants, and a separator that can be used for this type of power supply device. The present invention also relates to a vehicle and an electric power storage including this power supply device.
2. Description of the Related Art
Power supply devices such as battery packs for vehicles are required which can supply high electric power. In order to accommodate a number of battery cells in limited space, the high power supply devices generally include rectangular batteries, which can efficiently occupy space. The rectangular battery includes electrode members, and a rectangular exterior container that accommodates the electrode members, and a sealing plate that seals the exterior case. A number of rectangular batteries are arranged side by side with electrically insulating members such as resin separators being interposed between the rectangular battery cells. After the battery cells and the separators are alternately arranged, the battery cells and the separators are securely held by bind bars or the like so that a battery block is provided.
Japanese Patent Laid-Open Publication No. JP 2010-287,550 A discloses a battery block 210 that includes a plurality of rectangular battery cells 201, electrically-insulating separators 202 that are interposed between the rectangular battery cells 201 adjacent to each other, end plates 204 that are arranged on the end surfaces of a battery assembly constructed of the rectangular battery cells 201 and the separators 202, and bind bars 205 that couple the end plates 204 on the both end surfaces to each other, as shown in an exploded perspective view of FIG. 23 and a schematic cross-sectional view of FIG. 24. In addition, the separators 202 form cooling gas-flowing paths 206 between battery cells 201. Cooling air can flow through cooling gas-flowing paths 206 and cool the battery cells 201. In addition, the surfaces of each of the battery cells 201 are covered for electric insulation by a bag-shaped electrically insulating sheet 211 (e.g., PET resin etc.) as shown in an enlarged cross-sectional view of FIG. 24.
This battery block 210 is held by a strong force of the bind bars 205. Also, when the battery cells are charged/discharged with a large current, the battery cells 201 will expand as shown in the schematic cross-sectional view of FIG. 24. As a result, the exterior container surfaces of the battery cells 201 will be pressed by strong forces of the separators 202. In order to form the cooling gas-flowing paths 206, each of the separators 202 has a sectionally rectangular wave shape. If a strong force is applied to an edge part 207 of this rectangular wave shape, this edge part 207 may damage the electrically insulating sheet 211 (e.g., PET resin sheet), which covers the surfaces of the battery cell 201. If the electrically insulating sheet 211 is damaged, the damage may reduce the reliability of electrically insulation between the battery cells 201 adjacent to each other.
The present invention is aimed at solving the problem. It is a main object of the present invention to provide a reliability-improved power supply device that can protect the surfaces of an exterior container even if a force is applied by expansion of battery cells to the surfaces of the exterior case, and a vehicle including this power supply device.